Use the Creative Grids 10 Degree Triangle Ruler to create Fans, Dresden Plates, etc. up to a finished size of 31-1/2 inches. Total ruler length is 16 inches. Sew together 36 of these 10 degree triangles to create a complete circle; 18 to create a half-circle; or 9 to create a quarter-circle. The ruler slides easily over the fabric until pressure is applied. Then, exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts!